Mercury's magnetopause represents an excellent “textbook” example of a plasma boundary with a ion kinetic scale density gradient potentially LHDI-unstable.
Previous space missions at Mercury – Mariner 10 [1]} and MESSENGER [2]} – did not bring an instrumental payload capable of providing simultaneous measurements of electric field in the lower-hybrid frequency range and of the electron distribution function. Therefore, the expected LHW physics at Mercury cannot yet be tackled from past observations.
However, the physics at these scales/range is exactly one of the main scientific objectives of the ongoing ESA/JAXA space mission BepiColombo [3]}.
Different plasma instruments onboard the Mio spacecraft will provide measurements of the electron distribution function (MPPE/MEA, Mercury Plasma Particle Experiment / Mercury Electron Analyzer) and of the electric field in the lower-hybrid frequency range (PWI, Plasma Wave Investigation) enabling the possibility to directly address the physics of Mercury's strongly inhomogeneous magnetopause.
In this section, we quantify the expected efficiency of LHDI electron acceleration at Mercury's magnetopause using the eQL model developed in our work in support for future BepiColombo observations.
